Door closers are designed to close an opened door after the door is released. The strength of the door closer may vary, depending upon such factors as the weight of the door and even upon individual preferences.
The present invention provides door closing apparatus incorporating a spring unit which is readily and easily adjusted to change the amount of force available to close the door.
In accordance with the specific embodiment about to be described, a door closer is attached to a spring unit which in turn is mounted on the door frame by a bracket. The spring unit comprises a torsion spring within a barrel-shaped housing which is mounted for rotation on the bracket. A retainer affixed to the housing engages one end of the spring to compel that spring end to rotate with the housing. A second retainer for the other end of the spring is rotatably mounted on the housing. This second retainer may be held against rotation with respect to the bracket by a ratchet which has a ratchet wheel on the second retainer and a retractable dog on the bracket. The ratchet wheel may be rotated by a tool when the dog is retracted to adjust the tension in the spring, while holding the housing against rotation.
Preferably, the door closer is capable of being adjusted to change the speed at which the door closes by rotating the closer cylinder. To rotate the cylinder, it must be disconnected from the door. A stop on the bracket engages an abutment on the housing to prevent the closer from snapping back when disconnected from the door. The stop and abutment are also of assistance when adjusting the tension on the spring in the housing.
One object of this invention is to provide a door closing apparatus having the foregoing features.
Another object is to provide a door closing apparatus which is composed of a relatively few simple parts, is rugged and durable in use, is easily adjusted, and can be inexpensively manufactured and assembled.